Underreamer



July 31, 1923.

, c. L. GII-:BELL

UNDERREAMER Filed Sept. l18. 1922 l WITNESS '26 NVENTOR Patented July31, 1923.l

vonnnrns L. 'GIEBELn or PENNsBoRo, WEST v1Rs1N1A,-Assie1\ionoFfoNn-.HAJLF- fro cHaR-Lns L. DUNHAM. or rnmvsnono, WEST VIRGINIA; v

To allwhomz'tmay concern:

Be it known that I, CHARLESL. GIEBELL, a citizenof the United States,residing .at

Pennsboro, in the countyof'Ritchieand State of West Virginia,have'invented certain new and useful Improvements Vin Under reamers, ofwhich the following is a'speci-` lication. v

yMy invention relates to certain new' andk tion are to provide'anunderreamer `which' may-'be readilyfattached to a stringfofrdrillingtools, which is simple in its construction and arrangement,"strong,durable: and efii-I cient in its use, formed 'of few parts,readilyassembled,"and comparatively inexpensiveto manufacture. I l

' .With the foregoingand other objetsv view, which will appear as thevdescription proceeds, theinvention-resides-in the combination andarrangement ofV `partsand in the details of Construetionas hereinafterde-v scribed and claimed, itbeing understood that changes in the preciseembodiment Vlof zthe inventionherein disclosed can be made withinthefscope ofV what is 'claimed Without departing from the spirit of theinvention.

- In' the Vdrawing 'forming a portionfof this specification and whereinlikenumerals'of reference designate" correspondingv parts throughout theseveral'viewsr--- "Figure'l is an elevation of 'an underreamerinfaccordancewith this invention with portions thereoffin-section; e

Figure 2 isa vertical elevationof the cutter expanden: i"

. '.Figure'f :isa .top planview'jof in A fthe extendedposition. Y. vv*45Y.

.Referring in detail to the'drawing lli-'de j notes the body portion ofthe underreamer having; its :lower portion formed with aver-fl tical andcentrally disposed stepped 'bore of four different diameters,comprisingthe eX- l pander-stem' bore`2,=-the 'spring'bre 3, the eX-pander bore 4, and 'the cutter shank :bore 5.

TheIbores 12,3, 4 andk 5` increase inY diameter relatively' to eachother iiiv the order named andfor the-purposertobe' describedl The upperend of the-body portion 'is formedV @will part or separate as jshanks 7'UNDERREAMER vApplicatlwn ledseptember 18, 1922. Serial No. 588,793.

lwith threaded portion l to permit of its attachment to a drilling stem.f i y A pairof opposed cutters 6, each provided with a shank 7 at itsupper end, and extending into the borev 5, are pivotallyfeonneetedtogether by meansof the pin 8, which extends throughy the body Vportion1 and Vshownin Figure 3, but Ywhenthe cutters 6 Y are contractedthefupper ends of theshalnks y il'idicatedV by the Vdash'lines, asat'll.- Y H I Slidably mountedfor vertical movement in the'bores 2,3 and,4f is the expanderele` ment comprising an `elongated stem l2 fandexpander 13. yThe upper end of the stem 12 extends through the springbore Bland into the small bore 2 and is formed with an elongated slot'lefor v'the passageof a. pinV 15 fcarried by the "body portionfl'. f Thepin'l not only limits the downward movement of Athe "expander element'and permits of its atftached assembly-in the/'body portion'l independentof the c utters, but also Vpreventsv rotation of the expander 13 within'the bores i `when inthe assembled position. y Y

Tlieflower facefof thel eXpanderf-lis 495l Ato. :the upper tapeld endsof the lShanks 7 -vwhen'lini contact with '.each'fotherjl and lisadaptedtoengag'e thelatter for lockingv the f V-cu'tterisv in theexpanded position@ v 'T 'formed with a reeessflG identical in Icontourcoil spring 17 'is 'inount'edfon theste'm,

112, having'.its.lower endseated on theeX` pander F13" and itsupper endabutting :against the Sh'ulder is "of the bore 3; "The function lofthefspring 417 normally forces 1057, v l

the 'expander -13 downwardlyfupon the VThe expander .is'pfurther4EJformedjvt'ith a transverse slot A19?* having 'an upperwall 2o taperingdownwardly fromme 'entrante 'i of each 'side of the `slet 19 to its'centenl of each of which tei'ininates in a. slot 22 vwhich communicateswith the expander bore t and is in registration with the respectiveentrances to the slot 19 formed in the expander 13.

An elevating lever23 is pivotally con-Y nected, as at 24, in the upperend of each of the .grooves 21.. Each of the .levers is curved toproject from the periphery of the body portion V1, and has its lower endformed with anl'inwardly extending` tapered arm 25 adap'tedto engagewith the tapered upper wall 2O of the slot 19 of the expander forelevating' the latter from'contact with the Shanks 7 when the levers areforced inwardly by contacting with the wall of Jdie well casing, therebypermittingof the. contraction .of the cutters 6 to also allow theirpassage through the well casing'. rllhe outward movement' of the levers23 is limited -by the contour of the recess 26 in which the levers 23are respectively connected.

lt will be noted that the action Vof the springA .17 will normally forcethe expander 13 downwardly causing' the recess lbrin the lower facethereof to engage the upper `ends of the shanks. 7 and draw themtogether thereby forcing the cutters 6 .to theexpanded position. fWhcndrawing` the underreanier froma well, the levers 23 uponenterinpr thelower end off the casing will be engaged by the casing wall and forcedinwardly causing thearms 25 to engage in the slot 19 and elevate the.expander 13 clear ofthe shan-ks 7 permitting of the contraction of thecutters v6 and allowing' their passage .through the Casing. Y

When the .underreamer is lowered into a well, the cutters 6 arecontracted by manually shifting thelevers 23viniwardly to velevate theexpander 13, and permit of their insertion .into the upper end of thewell. casing. As soon as the device passes the lower .end-of the wellcasing` vthe spring' 17 Ywill function to force the levers 23 outwardlyand the expander 113 downwardly toV engage .the shanksr'andghold thecutters@` in the expandedor cuttiaigposition. Y. f Eachof .the .cutters6 has its upper formedfwith a pair of parallelextendingrecesses 27..@The recesses 27- of VVoiieof."the

.cuttersrG ai'e. in alignment with the recesses Y QZiof .the otherofsaid cutters G, when the vcutters 6 arein .the expanded position, The

.lower face ofthe body portion 1 is formed with'. [depending projections(not showfn)y Awhich. engage the .respective recesses E27 of the cutters6 and bear the torsional twist/or y strain to whichV the; cutters .Garesubjected during: the reainingoperation which otherwise would beborne'by theV pin 8 whiclicoii nects the cutters 6 :with thebodyportion. Y

The construction of the cutters 6 is such as to provide a clearance 28between their lower ends and the inner wall of the well casing whencutters 6 are contracted to pre- Vvent we Ir to the said ends andfacilitate the downward passage ofthe `reainer through the well casing.

Vhat l claim is 1. A reamer comprising' 'a body portion havingits lowerend provided with a central4 bore, cutters having' shanks extended intosaid bore, said slianks having interengaging means for pivotallyconnecting' said cutters to the body portion, a spring' actu atedexpander vertically shiftable in said bore and adapted to engage saidShanks for expanding Said cutters, said expander formed intermediate itsends with a transe versely extending` opening' having` one of its wallsoppositely bevelled, and means mov-v able towards and pivotallyconnected at the upper vend to said `body portion and having; the lowerend'provided with inwardly extending tapered arms V-engageable in saidopening to coaet with said. bevelled wall to elevate said expander topermit of the contraction of said cutters.

2. A reamer for the purpose .set forth comn prisingincombination, bodyportion having its lowerjend provided with a centrally disposed bore ofvarying' diameters, cutters having' shanks extended into said bore, saidShanks having interengagin.Q` means for pivotally connecting' saidcutter to said body portion, eachof said shanks 'having` its inner faceinclined outwardly and its outer upper end formed with a curved taper,anexpander provided with a stem mounted in said bore and vertically.shiftable therein, the lower face of said expander being' recessed andadapted to engage said tapered upper ends of said Shanks for expanding;Fthe latter, a. spring mounted on said stem and normally holding saidvexpander in engagement with said `shanks, means enga-ging' said' steinto prevent rotation of said lexpander within said bore, said expanderformed 'with a transverse slot having- 'a depending4 upper wall, a pairof levers having. tapered arms pivotally connected to said body portion.sai-d vtaiiered arms adapted tel engage said depending upper .wall ofsaidfs'l'ot for disengagingr said expander from .said Shanks to permitof the contractiencf said cutters when saidlevers are engaged bytheinner wall of 'a' well casing' on .its passage therein openings,-expandableY cutters extending4 into tne 'lower `end ofisaidbody, aspring Y vided with inwardly extendingarms operat-l 1,463,316 v Y 3 v Ycontrolled expander element co-operating with said cutters, saidelementarranged in said body and having its lower portion formed with atransverse opening, and oppositely' curved levers mounted in saidgrooves and having their upper ends pivotedy to said body and theirlower portions protherefor provided with 'an opening, Ia support for thecutters and element, and swinging levers, each pivoted at one end tosaid support and having an inwardly extending arm Yremoved from itslother end, said arms extending into said support and engageable in theends of said opening to elevate/said y elementto permit of thecontraction of the cutters.

5. A reamer comprising expandable cutters, a spring controlled expanderelement therefor Vprovided with an opening, a support for the cuttersand element, land swinging levers, each 4pivotedat one end to said` Ysupport and having an inward-ly 'extending arm removed from its otherend, said arms extending into said support and engageable in the endsofsaidopening to elevate'said elementto permit of the contraction of theproject from said support Vand oppositely curved with respect to eachother, and said,

support having means to limit the outward movement of the levers. v Y

In testimony whereof I aflix my signature.

CHARLES L. G-IEBELL.

y cutters, said levers curving in a direction Vto

